Field of the Invention
The present invention generally relates to an electrical bicycle derailleur. More specifically, the present invention relates to an electrical bicycle derailleur that facilitates movement of a movable member of a chain drive transmission.
Background Information
A bicycle typically uses a chain drive transmission for transmitting a pedaling force to a rear wheel. The chain drive transmission of a bicycle often uses derailleurs to selectively move a chain from one of a plurality of sprockets to another for changing speeds of the bicycle. A typical derailleur includes a base member, a movable member supporting a chain guide and a linkage (e.g., a moving mechanism) coupled between the base member and the movable member so that the chain guide moves laterally relative to the base member.
Recently, derailleurs have been equipped with motor units to make shifting gears easier. The motor unit drives a first link axle positioned close to the base member. The rotational driving torque from the motor unit is transmitted to a second link axle positioned close to the movable member through a transmission member, such as a belt or gear.